In terms of precipitation, rainfall in South Sumatra ranges from 3.5 - 13.0 inches per month. December is typically the wettest month, when rainfall can reach 13.0 in. August is typically the driest time to visit South Sumatra when rainfall is around 3.5 in.
If weather is an important factor for your trip to South Sumatra, use this chart to help with planning. For those seeking warmer temperatures, May is the ideal time of year to visit, when temperatures reach an average of 82.4 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 78.8 F).